Is it possible get a link from the journal entry created by the time entry? We need to determine the actual tasks that was used for the registered hours and resulting in the journal entry but I can't seem to find a link to get this information

I have never tried this but you might create a custom field and have saved search as result with "Created from" field. and show that on the record you want to show it on.

The thing is, the journal entry from post time doesn't have a created from

Try posting this in #C298P0BCK or #C29J1BPM3 channel, Project channel doesn't have much traction, I haven't worked much with Post Time Aspect of NetSuite, it is little tricky though, that's all I remember.