We have 2 group types. There is a difference in how they treat the merged filters.
First one is Simultaneous: Matches needs to be picked at the same time from all filters.
Second one is Sequential: Matches can be picked any time throughout the match no matter when other filters in this group picks same match. For example first filter picks match only once in first half, second filter picks match only once in second half and this group type will select that match as picked.
Let me show you very simple example. You have Filter A - Half time needs to be first half. And you have Filter B - Half time needs to be second half.
If you choose simultaneous group type, it will never pick match. Because these conditions never happen at the same time. In one moment can not be first half and also second half.
If you choose Sequential group type, it will pick match and send you notification in second half. Because Filter A will pick match in first half, than this group type will wait, and after Filter B pick match in second it will send you notification.
Now let's look at a possible scenario from practice.
You want to pick some interesting match in first half where is good potential to place bet - both team to score. But you will try to place bet in second half and only if your team start playing well at the beginning of the second half. So you need to define 2 filters.
Filter A - Both team to score (whole match filter type)
Filter B - Good start in second half (last minutes filter type)
And now you want to make one group from these filters. If you choose Simultaneous group type it wont work, because both filters must pick match in same time. And this situation will never happen. Because we have already condition in Filter A: Time needs to be first half. And Filter B works with last 10 minutes if time is greater than 55:00 (so there is second half).
Filter A picked match, Filter B not picked match = notification will not be send!
If we choose Sequential group type it will work, ecause there is no need for both filters to select a match at the same time. So Filter A will pick match in first half and now we are waiting. And if Filter B pick a match in the second half, we get a notification.
Filter A picked match, now waiting, Filter B picked match = notification will be send