I found the following users who may fit your language exchange criteria:

Username	Date	Post Link	Relevance	Offered Matches	Sought Matches
u/verde_pipistrello	2021-11-23	Post	`5`	German	Russian
u/lamusicista	2021-09-20	Post	`5`	German (C1)	Russian
u/zqom	2021-11-04	Post	`5`	German (Native)	Russian
u/gruene_ente	2021-10-14	Post	`5`	German (Native)	Russian
u/barzhikev	2021-09-26	Post	`5`	German (C1)	Russian

Please feel free to comment on the above posts to get in contact with their authors.