One of the most important tasks for decision-making systems is obvious and intuitive visualization of input data. If they are displayed correctly and conveniently, this tool can become a very serious assistant for a decision-maker. Such a tool influences not only on the complexity of the decision-making process, but also the correctness and objectivity of the decisions made. Because of this so much attention is paid to this issue in various studies. However, nowadays the issue of displaying the dynamics of changes in structured data (data in which the observed value has an internal structure and consists of a large number of components) is not sufficiently developed. This paper focuses on these issues, provides a formal description of structured data, and suggests an approach to displaying the dynamics of their changes. The proposed approach to visualization allows to see both the general process of changing the observed value and the nature of changes in its internal structure. Separate charts give the opportunity to see the contribution of each component of a structured value and evaluate the dynamics of this contribution over time. The paper also shows the area of potential application of this approach, highlights its features and main prospects. Most of examples in the paper are based on the developed software package for modeling the situation with the spread of COVID-19 in Bryansk region, which used the proposed visualization option. There are also examples in which the proposed approach to visualization helps to get new information that is not visible when using other approaches to displaying structured data.