thanks you both for interest
this is the gallery in the first run. I have almost 7k records, and it shows only 307 that are the records with "comuneID" blank

then i click on filter button to open the filters and i set the cbcandidatifiltrocomune to the first city in the list and it shows nothing (actually i don't know if i have some guy in that city)

the i set that combobox to blank and it shows 2000 records, that's the max value i can get with delegation (maybe you can suggest me how to overcome delegation in count rows)

i tried the suggested formula
Filter(
Candidati;
StartsWith(
Cognome;
TBcercacandidato.Text
) && (IsBlank(TBcandidatifiltroptftrasferibile.Text) || DPcandidatifiltroptftrasferibile.Selected.Value = "=" && 'Ptf trasferibile personale' = Value(TBcandidatifiltroptftrasferibile.Text) || DPcandidatifiltroptftrasferibile.Selected.Value = ">=" && 'Ptf trasferibile personale' >= Value(TBcandidatifiltroptftrasferibile.Text) || DPcandidatifiltroptftrasferibile.Selected.Value = "<=" && 'Ptf trasferibile personale' <= Value(TBcandidatifiltroptftrasferibile.Text)) && (ComuneID = CBcandidatifiltrocomune.Selected.IDComune || If(
IsEmpty(CBcandidatifiltrocomune.SelectedItems.IDComune);
true;
false
))
)
the default value and defaultselecteditems are just blank
thanks