On an organisational level this is a product of insufficient structure.

You can work on addressing matters of culture and individual attitudes but that's a long-game thing and it may not yield results or it may take a long time to yield results at all.

To address this on an organisational level, you want a chairperson and that chairperson to be an assertive moderator.

An agenda is also important as it will introduce and frame the topic for discussion, giving the chair an opportunity to pull people up if they're way off topic.

Establishing approximate timeframes for each item on the agenda is also important as it puts a degree of pressure on people to be succinct instead of treating the meeting as an opportunity to yap.

A chair will be able to use these timeframes to rein in people who are talking too much - if there is 15 minutes to discuss an item on the agenda and one person has taken up 5 minutes of airspace, the chair can move the discussion on to another person.

It's a tricky balance to try and strike and it depends on relationships and awareness and communication ability to navigate this stuff effectively and with sensitivity but as general advice if the chair has to continually drag one or two people back to the topic at hand as well as cutting them off because they're taking up all the time for discussion in meetings then there's a fair chance that these people will start developing an awareness of their behaviour and, if things go well, they'll start making improvements without any escalations or the need for other, more direct interventions.