Extradimensional Spaces

A number of spells and magic items utilize extradimensional spaces, such as Rope Trick, a bag of holding, a handy haversack, and a portable hole. These spells and magic items create a tiny pocket space that does not exist in any dimension.
Such items do not function, however, inside another extradimensional space. If placed inside such a space, they cease to function until removed from the extradimensional space.
For example, if a bag of holding is brought into a Rope Trick, the contents of the bag of holding become inaccessible until the bag of holding is taken outside the Rope Trick.
The only exception to this is when a bag of holding and a portable hole interact, forming a rift to the Astral Sea, as noted in their descriptions.