Institutional performance assessment is one of the major challenges for various stakeholders including national and institutional policymakers. Existing popular approaches to performance measurement rely on various factors besides research output, which have been criticized on various grounds. In this work, we present a sciento-text framework to assess the core competency/expertise of an institution at two levels: a broad thematic level, based on WoS subject categories, and a finer thematic level based on indexed keywords. The performance measures namely x_d- index and x-index are used for assessment at broad and fine thematic levels, respectively. While national policymakers can make use of x_d- index for the enhancement of national scholarly ecosystem, institutional policymakers and other stakeholders of the institution can make benefit from the wholistic usage of the framework to work for improving its broader expertise diversity as well as enhancing its fine level expertise within suitable disciplines.