Hi Pankaj, There is no standard object project so I am not sure how your data model is structured, Looks like your opportunity product has a relationship with project object and you would like to put a filter on projects you can add on product, you can definitely use lookup filter on project using an opportunity field as opportunity is parent on product. https://help.salesforce.com/HTViewHelpDoc?id=fields_lookup_filters_defining.htm
Explain your problem in detail, if this didnt solve you issue.
There is no standard object project so I am not sure how your data model is structured, Looks like your opportunity product has a relationship with project object and you would like to put a filter on projects you can add on product, you can definitely use lookup filter on project using an opportunity field as opportunity is parent on product.
https://help.salesforce.com/HTViewHelpDoc?id=fields_lookup_filters_defining.htm
Explain your problem in detail, if this didnt solve you issue.
Thanks,
Fahad Akhtar
yes, It was my mistake that is not project it is product