Wellwater
Just a flurry of H₂O
You'll need to edit your filter to move the hidden tag from the main list to the complex hide filter box, then, on the same line, put @,-artist:whoever@.
So, for example if you were hiding [text only], but wanted to see posts by [artist:abc123example], you'd go to the Filters page in the topbar, click to Edit the filter you're currently using, find [text only] in the list of hidden tags, click the X to take it out, then type @text only,-artist:abc123example@ in the Complex Hide Filter box and save the filter.
So, for example if you were hiding [text only], but wanted to see posts by [artist:abc123example], you'd go to the Filters page in the topbar, click to Edit the filter you're currently using, find [text only] in the list of hidden tags, click the X to take it out, then type @text only,-artist:abc123example@ in the Complex Hide Filter box and save the filter.