How do I get all the datamines when hacking?

To collect a datamine, you need to fill that sequence somewhere in the buffer above. It is possible to collect all if you're able to input the required codes for each.

Individual codes could be part of multiple sequences by overlapping them within the buffer. So you would want to try to chain those sequences together within the given buffer size.

e.g.,

1 - ABBA
2 - BBAC
3 - ACEA

Buffer - ABBACEA
         ABBA
          BBAC
            ACEA

The larger your buffer is, the more code points you could fit giving you more chances to get more datamine sequences at once.

In this particular case, I cannot see a sequence that would fit in the buffer to be able to collect all at once. Your buffer size is 6 and you could get v2 and v3 with the sequence 55 E9 BD 1C BD but not be able to fit in v1. Fortunately, this sequence is also possible to get with this matrix.

I would first try to come up with a sequence that would collect as much as you can first, then see if this sequence could be selected within the given matrix. This won't always work, so you'll have to either look for a different sequence or decide which is the better option.

I noticed the higher the datamine level, the higher the quality rewards you receive. So I would prioritize the highest version datamines.

This may be a bug but if you do not like the matrix you are given and/or the datamine sequences available, you could exit the hack and try again and you will be given a new matrix and new sequences with no apparent penalty. Just be careful how many times you do this within a play session, I exited too many times apparently and I was not able to do any datamine hacks (the minigame just crashes and nothing happens).