How to list notes with tags that start with "a" or "b"?

I want to get a list of notes and some of their tags. If I use the join function:

list join(filter(file.etags, (tags) => startswith(tags, "#đct")), filter(file.etags, (tags) => startswith(tags, "#tt"))) 

then it only returns tags start with #dct, with one tab for each element:

If I use the list function:

list list(filter(file.etags, (tags) => startswith(tags, "#đct")), filter(file.etags, (tags) => startswith(tags, "#tt"))) 

then it returns both tags, but each will be in two tabs:

Is there a way to make this cleaner, i.e. all the tags are in the same line with the title?