Neb. Rev. Stat. § 25-21,152

Any person interested as or through an executor, administrator, trustee, guardian, or other fiduciary, creditor, devisee, legatee, heir, next of kin, or cestui que trust, in the administration of a trust or the estate of a decedent, an infant, person with a mental disorder, or insolvent, may have a declaration of rights or legal relation in respect thereto: (a) To ascertain any class of creditors, devisees, legatees, heirs, next of kin, or others; or (b) To direct the executors, administrators, or trustees to do or abstain from doing any particular act in their fiduciary capacity; or (c) To determine any question arising in the administration of the estate or trust, including questions of construction of wills and other writings.