Although the dataset is not about 5G network slicing, but you might be interested in this dataset: https://www.kaggle.com/datasets/smmehedizaman/path-loss-at-5g-high-frequency-range-in-south-asia?fbclid=IwAR3PT5O-YBLuEXlrjo7oAi4Cv5avdT6QvIxMghwIreEql2_KmiW3hCKnYCE