Home field belongs to the higher seeded team in the first round.
For the second, third and fourth rounds, home field advantage is awarded as such:
1. The team that has traveled the most will be the home team regardless of seed.
2. If travel is equal, then the higher seed will be the home team.
3. If travel and seed is equal, the team that is on top of the bracket (as it is shown above) will be the home team.
The only rule that trumps all of the above rules is if the two teams are from the same region. Head-to-head does NOT matter, it is strictly based on seed within the region. The higher seed will host when from the same region, no matter what.