Table partitioning filegroup
Technically you can assign any existing/new filegroup to any new partition scheme (for other table). 

However, you need to understand the existing partition function and scheme design, and more importantly the purpose of the existing partition. It could be partitioned for improved scalability and performance reason by having filegroup on different disks. Or it could be partitioned to archive older data on slower and cheaper disk. Or partitioned on a same/different disk for quicker subset access like during data loading process. So, the idea is to find out if the purpose of the new table partition inline with existing partition to determine if existing or new filegroup should be used.