Find the number of matches of values ​​in a multidimensional array?

Question

Arrays

There is an array of unique values: [a1, b2, c3, v4, ...]
And there are many arrays where combinations from the array above are found:
=[
[a1, c3, v4],
[c3, b2],
[a1, b2 , v4],
...
]

How to find the number of intersections of each value with others? Those. a1 occurs together with b2 "X" times, c3 occurs together with v4 in arrays "Y" times?