for CRM Activity how i can add a filter on Mobile No. (in Extra Information tab of a Lead) but it should have a List of Mobile numbers to select (like a Many2one field), after user select from distinct list of Mobile numbers, it will show the related data.

please help with example or at least inform about is it possible or not? or any other workaround?

NOTE: i have to use Settings -> Technical  OR  debug icon 

regards