Time entries query through multiple projects by issue custom field not possible anymore.
This is related to #24014
Sometimes it might be necessary to for example show all time entries logged against issues with a certain custom field set to some value, regardless of what project the time entry and issue are in. If one subproject is not a subproject of the other, this is not possible anymore in one query.
I can understand the concern raised in #24014, but I think restricting the global query to only issue custom fields that are "for all projects" is too restrictive. I can understand that there might be many issue custom fields, but those should only be restricted on the project time entry query, not on the global time entry query.
While researching for this I have also noticed that an issue custom field defined in a subproject will not be available anymore in the time entry query of the parent project unless the parent project also has this issue custom field defined.
I propose to show all issue custom fields (maybe limited to those active on active projects?) on the global time entry query and to show only the issue custom fields active in the current project and its subprojects on the project time entry query.
(Please note that the same problem exists on the global issue query and that it could be solved the same way)