Hi @RandyHayes , I followed your suggestion and Hovered the mouse to the FirstName and LastName fields and looked at the details below of the browser.

It is showing field_1, field_2 and so on. I tried using the formula :
Search('Customers_GS_Sheet', TextInput1.Text, "field_1", "field_2")
and it is now filtering. Thanks for this! Much appreciated.
Is there a way to rename the field_1, field_2 to a more descriptive name?? like field_1 should be FirstName and field_2 should be Last name and so on. Thanks again!