You're right to ask for a more comprehensive list. Ohio, and Columbus in particular, is a fascinating hub for diaspora communities, and your examples are spot-on. Here is a detailed breakdown of the communities you asked about, plus several others with a significant presence in Ohio, based on the search results.

🗺️ Diaspora Communities in Ohio

Community Primary Location(s) in Ohio Significance / Population Estimate Key Details from Search Results
Somali Columbus (particularly Northland, North Linden areas, zip codes 43211, 43224, 43229, 43231) Second-largest Somali population in the U.S. . Official estimates ~26,000; community estimates closer to 60,000 in Ohio . Began arriving in early 1990s, fleeing civil war. Attracted by jobs and affordable housing .
Haitian Springfield An estimated 12,000 to 15,000 Haitians live in Springfield, making up as much as one in four residents (city population ~60,000) . This community has been in the national news recently and is a major part of the city's fabric .
Bhutanese-Nepali Columbus Columbus is home to the largest concentration of Bhutanese people outside of Bhutan, with around 30,000 residents . Began arriving as refugees in the late 2000s. Their deep agricultural roots are visible in community garden programs across the city .
Spanish-Speakers Columbus, Lorain Spanish is the most common non-English language spoken in Columbus homes, with over 56,000 speakers . In Lorain, about 30% of the population claims Hispanic ethnicity, with a strong Puerto Rican heritage dating back to the 1940s . The community in Lorain is well-established, originally attracted by work in steel mills .
Arab / Middle Eastern Toledo Toledo has the largest Arab community in Ohio. The community grew through the 1960s with families from Lebanon, Syria, and Palestine . Columbus has also seen a significant increase, with the number of Arabic speakers nearly doubling to over 15,000 between 2019-2022 . The growth in Columbus is partly due to recent arrivals of Afghan refugees and others fleeing conflict .
West African Columbus Speakers of West African languages (like Yoruba, Twi, Igbo) increased to over 12,000 in Columbus . Zip codes 43231 (Ghana, Kenya) and 43229 (Ghana) are key areas . This is a rapidly growing and diverse community encompassing many nationalities.
Eastern European Cleveland (Slavic Village, Parma), Columbus Cleveland has historic and large populations of Polish, Czech, Ukrainian, Slovak, Slovene, and Hungarian descent. Parma has the largest Ukrainian population in Ohio . Over 42,000 Ohioans claim Ukrainian heritage . While these are long-established communities, they are foundational to Ohio's identity. The Slavic Village neighborhood in Cleveland was named for its Polish and Czech settlers .
Indian & South Asian Columbus Columbus is home to a growing community from India. Zip code 43219 lists India as a top country of birth . Nepali, Marathi, and other Indic language speakers total over 11,000 in the city . This population includes both highly skilled professionals and refugees (like the Bhutanese-Nepali).

This overview shows that while your examples of Somalis in Columbus, Haitians in Springfield, and Bhutanese-Nepali in Columbus are accurate, they are part of a much larger and more diverse pattern of immigration that has shaped Ohio.

If you are interested in a specific community or city, or perhaps the history of how these communities came to settle in Ohio, feel free to ask