Hello, Guiles.

As our friends from Cybrosys commented in this post, the journal groups are for reporting purposes.

E.g. In my General Ledger report I want to display the information of only my Domestic Banks:

The better your information is organized, the better insights you will get, therefor, better decision making for your business.

Reply : In Odoo Accounting, Journal Groups serve as a way to categorize and group journals together based on their specific purposes or functions within the accounting system. Journal Groups provide a logical and organizational structure to the journals, making it easier to manage and track financial transactions.

Here are the main purposes of Journal Groups in Odoo Accounting:

1. Clear Segmentation: Journal Groups help in segmenting different types of financial transactions or operations within the accounting system.
2. Improved Reporting: By categorizing journals into different groups, it becomes easier to generate accurate and detailed financial reports. 
3. Control and Security: Journal Groups enable better control and security over financial transactions.
4. Workflow Management: Journal Groups facilitate the setup of specific workflows and approval processes.
5. Integration with Other Modules: Odoo Accounting integrates with other modules within the Odoo ecosystem.

Regards,

Ksolves Team!