we prefer English language here for our international users. So I translated your post:
I have two groups:
Group1
Group2
Both groups are to access a share.
Share1
Group1 with Read only
Group2 with writing and reading.
Do I have to make two share now?
No, there is no need for two shares.
Usually I would recommend to use either-or permissions. Either configure your share through the Linux permissions (the rwxrw-r-- stuff) OR configure through Windows-ACLs. For the later you need to grant all Linux permissions.