filter on process variable uidesigner

Hi,
I have stored in process variable tabellaPazienti a result of a query on mysql that contains the firstname and lastname of a user. For user in organization I use Api like this
…/API/identity/user?p=0&c=10&s={{cerca}} where cerca is my dinamic string in uidisegner and the filter go.
Can I use the same filter on a process variable tabellaPazienti
…/API/bpm/activityVariable/{{taskId}}/tabellaPazienti
Hope someone can help me
Regards
Monica