All other hydrogens are obviously constitutionally homotopic with the black hydrogen (and with each other) because each is connected to a carbon that is connected to another hydrogen and two carbons, each of which... Allowing the ring to flex allows converting the environment of any hydrogen to that occupied originally by the black hydrogen. You don't have to break bonds to do this, so the hydrogens are all configurationally homotopic with the black one, and with one another.

The Green hydrogen is conformationally diastereotopic with the Black one. It points in toward the center of the ring more than the black one does. Note that the carbon to which the green atoms is attached is also nearer the center of the ring than the carbon to which the black atom is attached. This means that the White hydrogen is also conformationally diastereotopic with the Black one. The Red hydrogen is conformationally enantiotopic with the Black one. (Note the mirror that is perpendicular to the screen and intersects it in a vertical line.) The Dark Blue hydrogen is conformationally enantiototopic with the Black one. (Note the mirror that is perpendicular to the screen and intersects it in an horizontal line.) If Red and Dark Blue are both conformationally enantiotopic with the Black one, what is their relationship with one another? The Pink hydrogen is conformationally homotopic with the Black one. (Rotation about an axis perpendicular to the screen and passing through the middle of the ring exchanges it with the black one)

The Yellow hydrogen is homotopic with the Black one. Sight along the line that connects the carbon with a pink hydrogen with the one with the black and yellow hydrogens. Note that this is an axis of symmetry. (Don't be disappointed if you missed this on initial inspection, it's hard to find.)