Regex Help: Combining two regexes as one regex with capturing

Setting up a variable name for user to select as a dropdown:

Currently I’m filtering on up{job=“my-running-instances”} as query

this outputs as a preview of values:

  1. up{instance=“",job="my-running-instances”}
  2. up{instance=“”,job=“my-running-instances”}

I can do this regex: /targetname=(.)",./
and this works for the for number 1

I can also do this regex: /.instance="("/
and this works for number 2

How can I combine these regexes with an OR ? (e.g. | )
Why can’t I simply do the following: /targetname=(.)",.|.instance="("/

Maybe I’m misunderstanding the function of the /'s

Any help would be appreciated, thanks.
Also if you have any good references online to further understand regex and how they work in grafana would be helpful.