@Anonymous
You can approach it from either the String perspective or the resulting split.
For example, with the split, you can use:
Filter(
Split("A|B|C|D", "|"),
!(Result="B")
)
This would return your Split without the B item.
Similarly, you can turn it back into a string if you just want to alter the string value.
Ex:
Concat(
Filter(
Split("A|B|C|D", "|"),
!(Result="B")
),
Result & "|"
)
The above would produce "A|C|D|"
And of course, you can just alter the string directly if that fits the scenario.
Ex.
Substitute("A|B|C|D", "|B", "")
That would produce: "A|C|D"
I hope this is helpful for you.