EU regulations govern interconnected domains, yet the hierarchical organization and granularity of regulatory semantic structures remain insufficiently understood. We analyze 717 provisions from nine EU regulations, represented as 746 embedding units, using K-means and Ward linkage. Two independently optimized 80-cluster solutions reveal recurring domain specific and cross-regulatory themes but differ in hierarchical organization. Cross-solution analysis shows high centroid-level semantic correspondence (mean matched-centroid cosine similarity = 0.943) despite lower partition agreement (ARI = 0.520; mean membership Jaccard similarity = 0.492). We identify 10 split and nine merge candidates, suggesting potential local differences in semantic boundaries or granularity. Post-hoc EuroVoc alignment shows partial agreement with established categories and identifies two qualitative candidate branches spanning taxonomy boundaries. These findings suggest that broadly corresponding regulatory semantic structures can coexist with local differences in membership, hierarchy, and granularity.