I have a lightning tabset and lightning tabs inside which I have buttons, on the click of which I should see different data. 
I want to add and remove slds-button_brand style in button as in the code. It is working for First tab but not for other tabs. Can anyone help on this.

Here is my code :

<lightning-tabset>
                <template for:each={FIInvestigation} for:item="FI">
				<lightning-tab key={FI.Id} label={FI.tabName} value={FI.tabvalue}>
				<span class="refHeading">Customer Residence Details</span><br><br>
                <lightning-layout multiple-rows="true" style="width:100%" class="slds-var-p-bottom_small slds slds-button_stretch">
                            <lightning-layout-item data-name="Individual" size="12" name="sstbutton" class="slds-var-p-bottom_small">
                                <div class="slds-m-top_medium" style="background-color: white;">
                                    <div class="slds-button-group" role="group" style="width: 100%;">
                                        <button data-name="sstbutton" data-btnlabel="SFEResidenceBtn" data-button={FI.tabvalue}
                                            class="slds-button slds-button_neutral slds-button_brand slds-button_stretch active"
                                            onclick={handleButtonClick}>SFE CVR</button>
                                        <button data-name="sstbutton" data-btnlabel="OnRollResidenceBtn" data-button={FI.tabvalue}
                                            class="slds-button slds-button_neutral slds-button_stretch inactive"
                                            onclick={handleButtonClick}>OnRoll FI</button>
                                    </div>
                                </div>
								<!--data-->
							</lightning-layout-item>
				</lightning-layout>
				</lightning-tab>
				</template>
</lightning-tabset>

 

loadcustomerInfo(leadID){
        getFIInformation({ leadId: leadID })
                    .then(result => {
                        if (result) {
                            console.log('FI Result -->' + JSON.stringify(result))
                            result.forEach(ele => {
                                this.value = this.value + 1;
                                let FI = {
                                        Id : ele.ApplicantId,
                                        Name : ele.ApplicantName,
                                        ApplicantType : ele.ApplicantType,
                                        tabName : ele.ApplicantType + ' ' + '(' + ele.ApplicantName + ')',
                                        tabvalue : this.value,
                                    }
                                this.FIInvestigation = [...this.FIInvestigation, FI];  
                            });
                            console.log('Field Investigation -->' + JSON.stringify(this.FIInvestigation))
                        }
                    }).catch(error => {
                        console.log('---error msg----->' + JSON.stringify(error));
                    });
    }
	
	hideandshow(){
        if(this.openpan == true){
            this.openpan = false;
            this.load = false;
        }
        else{
            this.openpan = true;
            if(this.load){
                this.loadcustomerInfo(this.recordId);
            }
        }   
    }
	
    handleButtonClick(event){
        if (event.currentTarget.dataset.name == "sstbutton") {
            console.log('inside sstbutton')
            if (event.currentTarget.dataset.btnlabel == 'SFEResidenceBtn') {
                console.log(event.currentTarget.dataset.btnlabel, event.currentTarget.dataset.button)
                this.template.querySelector(("button[data-btnlabel=OnRollResidenceBtn], button[data-button='"+event.currentTarget.dataset.button+"']")).classList.remove('slds-button_brand');
                this.template.querySelector(("button[data-btnlabel='"+event.currentTarget.dataset.btnlabel+"'], button[data-button='"+event.currentTarget.dataset.button+"'] ")).classList.add('slds-button_brand');
                this.SFEResidence = true;
                this.OnRollResidence = false;
            } 
            else if (event.currentTarget.dataset.btnlabel == 'OnRollResidenceBtn'){
                console.log(event.currentTarget.dataset.btnlabel, event.currentTarget.dataset.button)   
                this.template.querySelector(("button[data-btnlabel=SFEResidenceBtn]")).classList.remove('slds-button_brand');
                this.template.querySelector(("button[data-btnlabel='"+event.currentTarget.dataset.btnlabel+"']")).classList.add('slds-button_brand');   
                this.SFEResidence = false;
                this.OnRollResidence = true;
            }
        }
    }