General overviews help manage multiple businesses, any company the player is in CEO or Director position should be included in the overview.
Production company / Sector / Net value / Available jobs [editable] / Wage [editable]
pvt person or Company / Sector / Net Value / USD / EUR / BRL - (USD equivelent per currency and/or total)
*Include a total of columns
pvt person or Company / Sector / Products - (USD equivelent per product and/or total)
*include a total of columns
Company / Land / Product1 - Price [editable] / Product 2 - Price [editable] / etc.
Company / Land / Rented apartments / Available apartments [editable] / Rent [editable]
These, and maybe more could help manage multiple companies.