Can't filter by text in disp_id

Summary

using instr on disp_id and can't filter on the result

Content

I have a variable in a report which has the following code

if(incidents.status_type=2, if(instr(incidents.disp_id,'cancel')>0,'Cancelled',if(instr(incidents.disp_id,'donation')>0 | instr(incidents.disp_id,'saved')>0 | instr(incidents.disp_id,'Direct Debit')>0,'Saved','Other')),'Open')

I want to filter a report that uses this variable so that only those where this variable is "Other" are returned. But I get the attached error.

I've tried with both the variable "$nomoniesstatus" as the filter, and the raw code, and neither work.