It’s gone.
There is only the hard & continual work that you need to do to earn new exposure; helping Google’s users by creating value, and providing better resources & experiences than competitors.
You can’t “get back” what Google took away
In the case of things like Manual Actions (penalties), or Automated Filters (algorithms), if Google has decided to ignore/devalue certain things, you now rank lower, because those scores are gone!
There’s no “quick fixes” either.
Using the “refresh” exploit won’t remove a Penalty!
It may trick a Filter, for a time (until Google get’s of it’s ass and actually fixes it).
Transferring to a new domain may work, until you get hit again.
Technical fixes won’t get stuff back either (if your technical/foundational SEO is that-bad, you may float back up … but that’s not a “fix”, that’s you, patching holes that shouldn’t have been there!)
If you want to “rank where you were”, you have to earn it.
This is Not the case for mistakes, minor failings, glitches or short-term screwups etc.
If you noindex a bunch of things, or nofollow, or disallow, or have server issues, you will – in most cases, return to where you were, (unless it’s been Months and Months!).
If you deleted a bunch of content, or failed to implement 3xx redirects, again – you can make the fixes and generally get things back on track.
When it comes to Migrations and Quality … it’s trickier, and usually takes longer!
(Months – but does resolve, eventually)
But … you have to remember … yours is not the only page/site, … you are not the only one making changes, … you are not the only one earning links etc.
So – even if you do “get your score back”, you may end up a little lower, because others increased!
