Show listbox fields based on expression in Textbox action issue

[#1]

Hi, im trying to create a button where all the fields for a specific expression will show on the listbox when i click a textbox with a action.

So one of the expressions i used in the textbox action with Toggle Select:

Field :

LanID

Search String:

='= count(DISTINCT {<Year={"$(vMaxYear)"},date={"<=$(vMaxDate)"},Month=,Day=,YearMonth= >}  LanID)'

and this works.

This is the expression that doesnt work.

='= sum(  {<Year={"$(vMaxYear)"},date={"<=$(vMaxDate)"} ,Month=,Day=,YearMonth= >}

aggr(count(DISTINCT {<Year={"$(vMaxYear)"},date={"<=$(vMaxDate)"} ,Month=,Day=,YearMonth= >}

{<LanID = {"=count(distinct  {<Year={"$(vMaxYear)"},date={"<=$(vMaxDate)"} ,Month=,Day=,YearMonth= >}  DocName)<=2"}>}LanID),LanID))'

How can i solve this ?