Access Array Value Using Index Variable that contains brackets [duplicate]

I'm having a simple issue that I've been beating my head against the screen trying to figure out. I have a variable $sceneArray that holds the array listed below. I also have another variable $locateRecord that holds something like ['opening']['scene2'].

Ordinarily, to get the value of scene2, I would just reference $sceneArray['opening']['scene2']. But in this case, I need to combine the two variables to retrieve that value. I have tried things like ${sceneArray.$locateRecord} but that isn't work for me either.

Would appreciate any hint!

EDIT: I have the ability to format the $locateRecord value in a different way if that can solve this. For example, I could structure it as opening>scene2 or opening,scene2 etc.

Array
(
  [opening] => Array
    (
      [scene1] => 1:00
      [scene2] => 2:00
    )

  [closing] => Array
    (
      [scene3] => 3:00
      [scene4] => 4:00
    )
)