One common reason why published packages are not visible in the Business App store is failing to select a category when the package was created.
To resolve this, under Marketplace > Packages, search for the package that you created, click on the 3 dots (options menu), and select "Change Categories". Once you select any of the store categories listed, the package will appear in the Business App Store tab under the selected category.
You can also adjust which packages appear in your store categories by navigating to Marketplace > Manage Store > Categories.
Also, if the package created is for a particular market, then in Business App Store of another market will not have the package visible.
In that case the package needs to be copied to the other market. This is by going to Marketplace--Package--Click on the 3 vertical dots to the right of the package--Copy.
Select the required market--Save and Publish.
The package will be copied and be available for the selected market.