If you have permanently deleted files from a database, then the entire database is essentially corrupted and unusable.
Many databases (including file geodatabases) use a set of files which must remain internally consistent between them. Any changes to those files outside of the application(s) that understand how the database architecture works will corrupt the database. Deleting any of the files will corrupt the database.
You could try to recover some of the remaining data using the Recover File Geodatabase tool in ArcMap.
If this doesn't work, you may be out of luck.
It may be possible to undo the damage by replacing the files exactly as they were before being deleted, but if they are permanently deleted (and not in the trash/bin), then that is not possible.
Do you have backups? You need to recover these fGDBs from backups if you do.
If you do not have backups, then the data is most likely permanently destroyed.
For future reference, you should never even open a .gdb folder in Windows explorer (or any other application that is not designed to work with fGDBs.
fGDBs are an inferior format to some other formats which manage the entire database in a single file (eg, geopackage, and other SQLitebased formats).