The phrase "a cluster of groups" is correct and usable in written English.
It can be used to describe a collection or aggregation of different groups that are related or share a common characteristic.
Example: "In the study, we observed a cluster of groups working together to address the environmental issues in their communities."
Alternatives: "a collection of groups" or "a grouping of groups".
In the cattle-herding community Ms. Parmar belongs to, one among a cluster of groups categorized by the Indian constitution as "scheduled castes," women were traditionally bound not just to their region or village but to the home.
The suit, brought by a cluster of groups, including the North Carolina NAACP, the League of Women Voters, and the US Justice Department, seeks to nullify several provisions in HB589, including the truncating of early-voting periods by seven days, the elimination of same-day registration, and the banning of out-of-precinct provisional voting.
At least one of those charged in connection with the riot belongs to a group called Hong Kong Indigenous, one of a cluster of outspoken groups calling for greater Hong Kong autonomy and even independence from China, the group said.
A cluster of orthologous groups (COG) is defined as individual orthologous genes or orthologous groups of paralogous genes (i.e. cluster C2.2+c1) [ 1, 41, 42].
In total, 13,651 unigenes were assigned a Cluster of Orthologous Groups classification.
Each gene was functionally classified by assigning a Cluster of Orthologous Groups (COG) number and its corresponding COG category [ 86].
Each gene was functionally classified by assigning a Cluster of Orthologous groups (COG) number [ 83] and a Gene Ontology (GO) number [ 84].
Each gene was functionally classified by assigning a cluster of orthologous groups (COG) and a gene ontology (GO) number [ 98, 99].
Additionally, each gene was functionally classified by assigning of a Cluster of Orthologous Groups (COG) number and its corresponding COG category and Gene Ontology numbers [ 49, 50].
Conserved hypothetical proteins BEWA_005690 and BEWA_005710 fall into a Cluster of Orthologous Groups (COG) with apicomplexan genes annotated as TRAP, sporozoite surface protein or microneme protein 2 [ 53].
Volodya called for ceasefire and presented Alec with his perforated target — a cluster of holes grouped reasonably close together, reasonably close to the bull's-eye.
