How to use ak.Array with index arrays to create a custom masked output?

Using a list comprehension.

Snippet:

import awkward as ak

my_indices = ak.Array([[0, 1], [0], [1]])
my_dummy_arr = ak.Array([[1, 1], [1, 1], [1, 1]])

result = ak.Array([
    [arr[i] for i in indices]
    for arr, indices in zip(my_dummy_arr, my_indices)
])

print(result)

Output:

[[1, 1], [1, 0], [0, 1]]