Complex sentence: It was originally applied in a religious context as the most sacred place within a sacred building (such as a temple), but in common usage can also be applied to mean any reserved, private, or much-valued place.
Split into simpler sentences: It was originally applied in a religious context to the most sacred place within a sacred building (such as a temple). However, in common usage can also be applied to mean any reserved, private, or much-valued place.