The West Division has existed for nine seasons, and in six of those nine seasons, the winning team also avoided playing the top two teams in the East in the regular season. The exceptions were the 2018 Northwestern team that lost to UM but beat everybody in the West, and 2016 Wisconsin, who also beat everyone in the West. For five of the nine years, the team that went undefeated vs. its West opponents won the division.
WEST DIVISION CHAMPIONS vs. Top Two Teams in the East
2022 — Purdue 6-3 overall, 4-2 vs. the West (didn't play Michigan or OSU in regular season)
2021 — Iowa 7-2, 4-2 vs. the West (didn't play Michigan or OSU in regular season)
2020 — Northwestern 6-1, 5-0 vs. the West (didn't play Indiana or OSU in regular season)
2019. — Wisconsin 7-2, 5-1 vs. the West (lost to OSU but didn't play PSU during regular season)
2018 — Northwestern 8-1, 6-0 vs. the West (lost to Michigan but didn't play OSU in regular season)
2017 — Wisconsin 9-0, 6-0 vs. the West (didn't play PSU or OSU in the regular season)
2016 — Wisconsin 7-2, 6-0 vs. the West (lost to OSU but didn't play PSU in regular season)
2015 — Iowa 8-0, 6-0 vs. the West (didn't play MSU or OSU in regular season)
2014 — Wisconsin 7-1, 5-1 vs. the West (didn't play MSU or OSU in regular season)
So, the answer is to beat everybody in the West — though the current level of parity suggests that's not likely — and to avoid playing the two best teams from the East, which are almost always top 10 or better teams nationally.
Who avoids the presumed top two in the East next year, Michigan and Ohio State? Iowa. Who gets home-field advantage against the only West teams with winning records, Purdue, Minnesota and Illinois? Iowa.
Imma go with the Hawkeyes next season on that alone.
BTW, Iowa and Nebraska are the only West teams that have had to play the top two East teams in the regular season:
2022 — Iowa 5-4, 4-2 vs. the West (lost to both Michigan and OSU)
2021 — Nebraska 1-8, 1-5 vs. the West (lost to both Michigan and OSU)
2018 — Nebraska 3-6, 2-4 vs. the West (lost to both Michigan and OSU)
2017 — Iowa 4-5, 3-3 vs. the West (lost to PSU but beat OSU)
2017 — Nebraska 3-6, 2-4 vs. the West (lost to PSU and OSU)
The only teams to play all three of the top East teams in the same regular season? The 2021 Cornhuskers played top 10 OSU, UM and MSU that season. The 2017 Hawkeyes played the top three that year, also losing to Michigan State in addition to Michigan and beating OSU.