Welcome, @hyena. You can certainly slice up a sample within the sample player, and control which slice gets fired by setting the mode to index, and then manually adjusting the index parameter to choose which slice is played by the trigger. There is no need for trimming if you do it that way.
So for example say you have a sample that contains a snare hit with some silence at the beginning and end of the sample. You could put a slice right where the snare sound starts, and a slice where the sound ends. The index parameter can then be used to select each of these three slices. You’d set index somewhere around the mid-point to select the middle slice, and that’s what the trigger will play.
Is this what you mean?