The way I was taught (via St. Augustine)–was that the three Persons of God share one Will–‘the Will of God’. They are never in conflict with one another, because they are of the same Will; it’s how we reconcile 3 persons, one God. If the Holy Spirit has a distinct Will from the Son, or the Father…the Holy Spirit would constitute a distinct ‘god’.
Now, wrt to Christ–Christ had a distinct Will incidental to His humanity–that is, His human nature. Had Christ exercised His human will contrary to God’s Will…Christ could not have redeemed Man. Christ would in essence have chosen His human nature, over his divinity; He would have essentially sinned, just as Adam had–leaving Man damned.
This is the significance of the temptation in the dessert by Satan; His struggle/suffering in the garden of Gethsemane; the torture via the Passion; and the ‘bad’ thief’s last temptation, when he dares Christ to invoke His divinity, to save His humanity–IOW, to subordinate His divine Will–the Will of the Father–i.e.–the Will of God–to His human will, which cried out for reprieve from the brutal, torturous circumstances, including excruciating pain, loneliness, hunger, thirst, extreme fatigue, desire for love, fellowship, acceptance, and such.
After the Resurrection (and certainly after his Ascension), Christ’s human will is no longer in effect; it has been absorbed (if you will), into His divine Will. There is no longer any internal conflict between the wants/needs of the flesh, and his divine mission.
Mission accomplished–*“It is finished”/I].
Upon the Ascension, He has returned to His Father, and sent in His stead, ‘the Advocate’/‘Paraclete’/‘Holy Spirit’–His (and the Father’s) Will, ‘personified.’
CAVEAT: this is just my humble understanding (acknowledging St. Augustine’s influence, directly, and via 2nd/3rd parties, interpreting/applying St. Augustine–especially wrt to the unity of the Will of the three Persons of the Trinity) . As always, I welcome dissent, correction, or the like; I make no claims to authority, and IMHO, this topic (very intriguing one, I should add), falls within the non-dogmatic area of Church teaching, that essentially leaves some wiggle room for interpretation–the above, simply reflects mine–that is, my humble reconciliation of the challenging concept of the Trinity, with/vis a vis the similarly challenging and ambiguous concepts of ‘the will’ and ‘the Will of God.’