<input type="multiselect" token="reason_token" searchWhenChanged="true">
<label>Filtro de Causas</label>
<search>
<query>| dbquery DB01 "select
idt_deduction as \"reason\",
des_deduction as \"desc\"
from deduction
where idt_deduction_group='$group_token$'"
| eval teste = $group_token$
| stats values(reason) as reason by desc
| eval Reason = reason + " - " + desc</query>
</search>
<fieldForLabel>Reason</fieldForLabel>
<fieldForValue>reason</fieldForValue>
<delimiter> , </delimiter>
<choice value="select
idt_deduction_reason
from deduction_reason
where idt_deduction_reason_group='$group_token$'">All
</choice>
</input>
I usual use something in the form of..
<input type="multiselect" token="reason_token" searchWhenChanged="true">
<label>Filtro de Causas</label>
<populatingSearch fieldForLabel="Reason" fieldForValue="reason">
| dbquery DB01 .....
</populatingSearch>
<delimiter> , </delimiter>
</input>
Your $group_token$
is not being set anywhere so it can never work. How are you planning to set it?