Selection from if constructed field

[Annek]

if(TIPEL_DESCRIZIONE = 'Comunali', LILE_DESCR_LISTA, LISTE_DESCR_LISTA)

When I selected this field, in case of TIPEL_DESCRIZIONE = 'Comunali', qlik makes two selections: one from LILE_DESCR_LISTA and some others from LISTE_DESCR_LISTA. I expected only one selection from LILE_DESCR_LISTA.

Please some tip?

[micheledenardi]

I suggest to put this logic during load script and create a new field for selections purpose.