If this is a buff on your target you could use the addon Srendarr to define some of the target buffs to show at a special movable buff bar.
You need to activate the abilityId finder to find the id of the buff that players/targets get and you are interested to see on the extra buff bar.
Then create the buff bar, add the abilityId (buff id) to that bar's whitelist and you should see those buffs ONLY at this bar if you move your mouse above an enemy/player and they have that buff active.
https://www.esoui.com/downloads/info...ffTracker.html
Example how a Briarheart cooldown on your self could look like on a movable self buff frame:
https://youtu.be/Y9C2lLgv3Cw?t=887
Multi target buff tracking:
https://youtu.be/fL6BRYOUBcg