How to use a formatter in a value help dialog?

Dear colleagues,

I am trying to use a formatter within a value help dialog. In oder to use the formatter I am trying to bind it within the definition of the columns of the value help:

 _oValuehelpModel = new sap.ui.model.json.JSONModel({
 "cols": [
 {
 "label": "{i18n>templateName}",
 "template": "templateModel>name"
 },
 {
 "label": "{i18n>templateType}",
 "template": "templateModel>type"
 },
 {
 "label": "{i18n>personalTemplate}",
 "template": "{path: 'templateModel>personal', formatter:'.formatTemplateVersion'}"
 }
 ]
 });

However this does not seem to function as there are no entries returned..

2020-10-30-15-36-33.jpg

The binding works without the fromatter.

If you have experienced a similar issue, I would be thankful, for your support.

Thanks,
Daniel