Yes! We've recently added this feature.

When generating a new version of your dataset, click on "Step 2" (Train/Test Split):

Roboflow dataset generation UI

• Next, select "Rebalance"

Roboflow train/validation/testing split Rebalancing UI

• Select your new desired Train/Validation/Test split by adjusting the sliders to their desired positions:

Roboflow train/validation/testing split Rebalancing UI

• Select "Save"

** Continue on with the Preprocessing and Augmentation steps to generate a version of your dataset with the new train/validation/test split

• NOTE: The Preprocessing step of "Tiling" will increase the number of images in your dataset. The Augmentationsteps will also generate more examples of your images. Application of Tiling, or augmentations, will result in more total images in your training set.
  • To keep your train/valid/test split balance exactly the same as the one you selected during "Rebalancing," do not apply Tiling (preprocessing) or any augmentation steps.

As a reminder, you can also choose to upload images to only training, validation, or test set if desired.