[13] looking for the blessed hope and glorious appearing of our great God and Savior Jesus Christ, [14] who gave Himself for us, that He might redeem us from every lawless deed and purify for Himself His own special people, zealous for good works. (Titus 2:13-14, NKJV)

From this verse we know Jesus is called "our great God and Savior" and then is described as having a special (or "perculiar") people for His own possession.

And when we read Deuteronomy 7:6 (and also Exodus 19:5 and Deuteronomy 14:2), the same applies to YHWH:

[6] "For you are a holy people to the LORD your God; the LORD your God has chosen you to be a people for His own possession out of all the peoples who are on the face of the earth. (Deu 7:6, NASB)
[6] For thou art a holy people to the Lord thy God; and the Lord thy God chose thee to be to him a peculiar people beyond all nations that are upon the face of the earth. (Deu 7:6, LXX)
[6] For thou art an holy people unto the LORD thy God: the LORD thy God hath chosen thee to be a special people unto himself, above all people that are upon the face of the earth. (Deu 7:6, KJV)

Just like Jesus, YHWH is called "God" and has a special, perculiar people for His own possession.

Paul uses the exact same Greek words from the LXX, for possession/special and people. This makes the connection between Titus 2:14 and Deuteronomy 7:6 rock solid. This parallel was clearly done intentionally by Paul. He wrote Titus 2:13-14 knowing fully well about what Deuteronomy 7:6, 14:2 and Exodus 19:5 say.

Greek words from Titus 2:14:
-Possession/special/peculiar: περιούσιος periousios
-People: λαός laos

Greek words from Deuteronomy 7:6 from the Greek Septuagint:
-Possession/special/percuilar: περιούσιον periousion
-People: λαὸν laon

So we have Jesus being called "our great God" by Paul and then he further proves Jesus is the one true God, YHWH, by applying Deuteronomy 7:6 to Him. Paul's application of Deuteronomy 7:6 to Jesus, proves Titus 2:13 does indeed call Jesus "God" instead of it being about the Father. Therefore when Paul calls Jesus "God" it means He is YHWH, according to Paul, not just "a god". And just as Jehovah is called "God" in both Deuteronomy 7:6 and 14:2, Jesus is in Titus 2:13. Paul did this deliberately. Titus 2:13-14 only describes 1 person, the Son, and it was the Son's glorious appearing being awaited for, not the Father's.