Help for DBKit.PopupMenu

In a “Window” called “Aanagrafica” I have three “PopupMenu” (DBKit.PopupMenu) called “reg_nasc”, “prov_nasc” and “luogo_nasc”.

The “Anagrafica” “Window” is connected to the SQLite db “loggia.sqlite” via “DBKit.TableConnection” called “ConnessioneFratelli” to the “fratelli” Table which has, among other fields, “reg_nasc”, “prov_nasc” and “luogo_nasc”.

The “loggia.sqlite” db has the “regione”, “prov” and “luoghi” tables having respectively the columns “id_regione”, “regione”; “id_prov”, “prov”, “id_regione”; “id_luogo”, “nome”, “id_prov”.

How can I ensure that when the "regione” value of the "regione” table is selected in the “reg_nasc” PopupMenu, only the “prov” values ​​that correspond to the selected “regione” are listed in the “prov_nasc” PopupMenu (regione.id_regione=prov.id_regione) and in the “luogo_nasc” PopupMenu are only displaayed the values ​​corresponding to the selected “prov” value listed in the PopupMenu “prov_nasc”(prov.id_prov=luoghi.id_prov)?