A motion under RCW 7.04A.050 must be filed in the court of the county in which the agreement to arbitrate specifies the arbitration hearing is to be held or, if the hearing has been held, in the court of the county in which it was held. Otherwise, the motion must be filed in any county in which an adverse party resides or has a place of business or, if no adverse party has a residence or place of business in this state, in the court of any county in this state. All subsequent motions must be filed in the court hearing the initial motion unless the court otherwise directs.