[@LadyAnnaLee] BG3 as a game is not necessarily an intensive game and the requirements reflect this. These are the specs:[table=bordered]
[row]
[cell]Minimum[/cell][cell]Recommended[/cell]
[/row]
[row]
[cell]CPU: Intel Core i5 4690 / AMD FX 8350
RAM: 8 GB
VIDEO CARD: Nvidia GTX 970 / RX 480 (4GB+ of VRAM)
DEDICATED VIDEO RAM: 4096 MB
PIXEL SHADER: 5.1
VERTEX SHADER: 5.1
OS: Windows 10 64-bit
FREE DISK SPACE: 150 GB[/cell][cell]CPU: Intel Core i7 8700K / AMD Ryzen 5 3600
RAM: 16 GB
VIDEO CARD: Nvidia GeForce RTX 2060 Super / RX 5700 XT (8GB+ of VRAM)
DEDICATED VIDEO RAM: 8192 MB
PIXEL SHADER: 5.1
VERTEX SHADER: 5.1
OS: Windows 10 64-bit
FREE DISK SPACE: 150 GB[/cell]
[/row]
[/table]

You can ignore [b]pixel shader, vertex shader, OS and free disk space[/b] since those are not usually influencable through the purchase. What matters most is the CPU, ram and video card. Since you are shopping for a laptop it is also important to remember that laptops typically under-perform by a significant margin due to heat throttling and other issues that result from the compact nature of a laptop. That said the recommended specs for BG3 are so low that most last- or current-gen laptops will be able to keep up. Any of the laptops listed in [@BrokenPromise]'s link are good and some are 'technically' overkill on the recc. specs (but recc. specs are usually not guaranteed to actually work, I think they are baselined on medium graphical settings, lol). 

If you are [b]only[/b] interested in BG3, aiming for between the minimum and recommended specs or a little above would probably be good enough. If you want to play other things or think you might be interested in other things later, it might be a good idea to overshoot a bit more (16gb of RAM is more than enough still nowadays, but having 32gb of RAM has gone from a luxury to a futureproof investment, for example). But it sounds like you're not really interested in that and that makes anything over the recommended specs almost automatically an investment that's not worth it at all.

You ask what to filter for, that's mostly going to be graphics cards, RAM and CPU. I do think buying a laptop specifically for BG3 is a bit of a waste of money, though, unless you also do graphical editing or video editing. Having a powerful CPU is also eventually going to give negligible returns. I think having extra RAM's nice in general, but going for a full 64gb is also useless for most common use scenario's and 32gb is also up there in terms of uselessness, but that is slowly but surely going to erode. GPU's are pricy and laptops specifically get overcharged like crazy for a product that is less powerful.

I think it might be easier to just post a laptop you saw that works for you, and then check if it meets the specs, since there are hundreds of configurations for laptops and they all have different benefits and costs.