Does decree of focus give +4 if i thrill of the hunt the fury unit to another battlefield.

No, Decree of Focus will not grant +4 Might in this scenario.

Reasoning

1. "New Object" Rule: According to Rule 359.3.e.4 and FAQ #9870, when Thrill of the Hunt banishes a unit and then plays it back to a battlefield, that unit is removed from play and re-enters as a new game object.
2. Severing Targeting Relationships: When a unit becomes a "new object," any existing targeting relationships or active modifiers tied to its previous state (as the "original" object) are severed.
3. Decree of Focus Requirement: Decree of Focus requires you to choose a unit "in combat with an enemy Fury unit." While Thrill of the Hunt moves the unit, the re-entered unit is a new object. Even if you were to cast Decree of Focus in response to the Thrill of the Hunt (to target the unit before it leaves the board), that effect would effectively fizzle or be removed because the unit it was targeting has changed into a new game object. If you attempt to play Decree of Focus after the unit has re-entered, the check for whether it is "in combat" will be evaluated based on the new battlefield situation, but the +4 Might will not persist from any previous state.

Summary: Because the unit becomes a new game object when moved by Thrill of the Hunt, it loses all previous modifiers and targeting relationships. You cannot use these cards to maintain or transfer a +4 Might buff in this way.

Note: I could not fully verify this ruling against the retrieved rules.