I've got this list that has the user mail as user datatype and a column also with user datatype, that has sharedmailboxes for the user in the record.

I need to populate a combobox whitn the 'Buzones compartidos' elements.
The filter is the 'Asignado a' Email that I store in a var once the user has logged in the app.
I'm getting this result

I've got a button to reset the collection wich has this function
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ClearCollect(collGestores;
Filter(Gestores;ThisRecord.'Asignado a'.Email = varEmailUsuario));;
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In the dropdown Items property I have this formula
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Distinct(Table(ShowColumns(collGestores;'Buzones compartidos'));'Buzonescompartidos')
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How can I get all values from the registry I'm filtering with the variable varEmailUsuario?
Thnx in advance!
Cheers!