Filtering Ditto Results by Multi-Select TV Values

This donor dealt with a familiar old-Evo problem: a TV stored several category-like values, and Ditto needed to filter resources by that multi-select field.

Example TV source

@EVAL return ' ||' . $modx->runSnippet("Quill", array('parent'=>'50', 'title'=>'pagetitle'));

Example Ditto call

[[Ditto?
  &parents=`2`
  &tpl=`collection.tpl`
  &depth=`3`
  &paginate=`1`
  &display=`16`
  &filter=`tvnew,,2`
  &extenders=`request`
  &sortDir=`ASC`
  &sortBy=`pagetitle`
]]

Where the confusion comes from

Multi-select TVs often store a value format that looks simple in the manager but behaves differently once filtering starts. The listing engine may need exact tokens, rendered values, or delimiter-aware logic, depending on how the field was configured.

Practical advice

If a TV is meant to drive filtering, decide early whether it is a human-facing field or a query-facing field. One field can do both, but the more categories and combinations it carries, the more careful the filter logic needs to be.