The definition of the seniority of the profile you are looking for a position will depend on different factors, especially related to the level of the position (e.g. a CTO must be an expert since it is a leadership position and requires a vast previous experience), to the technical requirements and functions that the professional must perform on a daily basis. You can review our seniority policies to understand what level of experience corresponds to the position you are looking for.
In technology, seniority is not given by the 'years' you have been in a position, but rather by the functions you have performed during that time. For example, a developer who has worked 5 years in a development position to support a platform will not have the same knowledge and/or level of experience as someone who has worked those same 5 years building an app from scratch.
In the first case, the professional probably has excellent database management and very good skills in detecting bugs and their corresponding repairs. In the second case, the professional may have an excellent base in development architecture, knowledge of agility, user stories generation, creation of new features, testing, etc.
So, if you specify '5 years of experience as a requirement, you are not clearly defining what the professional should be able to do. That is why the 'Job functions' are as important (or even more important) for the definition of the role and the seniority you are looking for.
You should keep in mind that the higher the seniority, the higher the salary your company should be willing to pay. If you do not have the budget to hire a Senior Dev (because these positions are in high demand), you can look for a semi-senior who can develop his/her career in your company, and gradually acquire more responsibilities until he/she has seniority that allows him/her to lead teams (and increase his/her salary little by little).
And remember that today's juniors will be tomorrow's seniors, so hiring juniors can be a great investment for the future of your company.