I want to configure a vsftpd in a per group fashion instead of per user configuration. It's possible?

Suppose i have two groups: groupA and groupB, so my goal is:

• users in groupA have permission (wrx) to all files in directory dir1
  
• users in groupB have permission (wrx) to all files in directory dir2
  
• users of the system have permission (wrx) to all files in directory dir3
  

For example:
ftp@test:/home/ftp# ls -l
drwxrwxr-x 16 root groupA 4096 Jun 3 10:45 dir1
drwxrwxr-x 2 root groupB 4096 Jun 3 10:56 dir2
drwxrwxr-x 8 root users 4096 Jun 3 11:01 dir3

How to do that with vsftpd?