We are using the LIghtning Experience.  I have a custom object and I would like to add a section on the page layout that would allow me to add one or more lookup fields for the same object (perhaps a link or button).  For example, the custom object is called "Investment Strategy" and I would like to be able to add all of a client's financial accounts (which is another custom object) that are associated with this particular "Investment Strategy".  I'd rather not create 10+ lookup fields as it crowds the form and it messes up some other items we are doing with document merges.  Any ideas?