If an expiation for a broken oath has been paid due to a partial breach of an oath to abandon a specific sin for seven months, is a new expiation required if the oath is breached again within the remaining period of the oath?

It is obligatory to avoid sin and to repent immediately from it by refraining from it, regretting it, and resolving not to return to it. The basic principle is that an oath is broken by the first instance of violating it, and expiation is not repeated, unless it was intended, or the wording necessitated it, or custom indicated it.