Can I play Teemo Scout hidden champion unit from champion spot to battlefield as long as I pay for the hidden?

Yes, you can hide a unit with the Hidden keyword directly from your Champion Zone.

According to Rule 737.1.b:

"While this card is in your hand or in the Champion Zone on your turn during an Open State, you may pay [A] to hide this facedown at a battlefield you control..."

Key Points:

• Direct Hiding: You do not need to move the card to your hand first; you can perform the "Hide" action directly from the Champion Zone.
• Timing: You must perform this action during an Open State on your turn.
• Cost: You must pay the cost specified by the Hidden keyword (typically [A], which represents one rune of any domain).
• Restriction: You can only hide the card at a battlefield you control that does not already have a facedown card hidden there.
• Playing the Hidden Card: Once hidden, the card cannot be played until the next turn. When you do play it, it is played from the facedown position at that specific battlefield.