Christian Rott said:
Jetzt hänge ich daran das ich die Spiele soweit auswähle und daraus die Sieger habe und diese sollen dann im nächsten Step gegeneinander spielen bis ein Gruppen Sieger feststeht.

So each group does not play every other group once? I see you have 8 groups. Do you only play four rounds (with some way of determining which group plays whom), then the winners of the rounds start to play each other?

Christian Rott said:
therefore I only want to select the winners for the next round at the groups selection

 In the Spiele table, how do you determine which round is being played? With 8 teams you need to track 3 rounds (8 to 4 to 2)

Next question: I'm not sure what you call the 3 rounds, but I'll call it an event for now. I'm sure you want to track many events. Is that true? 

Well here is a version 1 of what is could look like.

There are a few changes.

1) a new table called Ereignis. I hope that is the correct translation. :) It is now the parent table to Spiele. Spiele has a new child table called GruppenInfo. I have removed the GruppeA and GruppeB fields from Spiele because it is not best practice to create fields that contain the same type of data. It is better to create a child table. Plus you needed a many to many (M:M) table so you can assign many groups to many spiele.

2) Gruppe has a new child table called Mitglied. Again now you can assign many participants to many groups.

So now you create a record in Ereignis and then add records to Spiele. When you select a round, it will show the correct number of groups. You will select the groups in Teilnehmer Auswählen then click on the Gruppen hinzufügen button.

If that is what you want then we can move the process to your dashboard.